Used often in processing sausage, loaf products, and other assorted value-added meat products , blending is a very delicate process.

Meat processors must closely monitor and control the blending process for a number of reasons. Excessive mixing can cause salts to break down excessive amounts of protein. Friction created by blending can increase product temperature and cause fats to partially render. Excessive handling also cuts protein fibers too short. Any one of these problems can result in product quality defects.

The blending process must also achieve uniform distribution of non-meat ingredients within the product formulation. For instance, flavoring, salt, and other ingredients must be consistently mixed throughout a sausage formulation.

For all of these reasons, the design of a mixer/blender is important. The current trend in blending today is in the design of the mixer itself, says Michael Botto, president of American Food Equipment Co. Inc., AMFEC Hayward, CA. “Manufacturers, driven by their customers, are looking to find ways to improve the sanitation aspect of the machine,” Botto says.

AMFEC mixer/blenders are designed and manufactured with polished interiors, with all welds ground smooth. Other features include quick-release shaft seals, solid shafts, and easy access for cleaning. “The design of the tub, agitators, and discharge all affect the mixing/blending abilities of the machine. Blender manufacturers need to have a product line of mixer/blenders that best provide the customer what the customer needs -- not just what the blender manufacturer manufactures,” Botto says.

When customers aren’t discussing capacity, they’re talking about the blenders themselves --  whether they’re paddle or ribbon, vacuum or non-vacuum, CO2 injection or not, and jacketed or not, says Tom Baumgartner, president of Barliant and Co., Yorkville, IL. His company sells used blending equipment to meat processors.

Beaver Dam, WI-based Mepaco has blending technology that offers a variety of agitation options from standard paddle, ribbon, overlapping paddle, and “rolled” ribbon for massaging, regardless of the size.

“Within this family of agitators are a variety of options to choose from for each application,” says Tom Hoffmann, vice president of sales and marketing. “In addition, vacuum, ASME code jacketing, steam injection, or CO2 injection are also available depending upon the process requirements.”

Mepaco is often asked to reduce blend and discharge times while reducing the standard deviation of the batch to a fraction of a percent, Hoffmann says. Because more customers are concerned with loss yields and compliance with sanitary design principles, Mepaco engineers its blenders for each specific application, whether it’s to slowly tumble a delicate product or rapidly mix a viscous one.

“This requires our staff to consider distinctive forms of agitation outside of the standard paddle- and ribbon-style blenders,” Hoffmann says. “Unique discharge options, speeds, and cycle regimens are determined for each application, regardless of species. In an effort to limit fat build-up and enhance cleanability, Mepaco also provides electropolishing and pickle passivation services.”

Electropolishing is effective in limiting product adhesion to side walls and agitators, ensuring that all blended product is effectively evacuated from the blender at the end of the cycle.

Botto says there are different types of mixer/blenders that best lend themselves to different product, layout, and production requirements. “Dealing with a supplier that offers a full range of mixer/blenders and who understands the customer’s business improves the customer’s chances of getting the machine that will work best for the customer,” he says.

But the challenge of achieving as homogenous a mixture of ingredients as possible is nothing new, Botto says. “This is necessary to meet government regulations on ingredient percentages, flavor profiles, weight control, and product appearance,” he adds.

To get maximum yield and consistent quality, high-shear mixers are needed in initial mixing to ensure full functionality of ingredients, says Peter Leitner, vice president of sales at Admix Inc.

Leitner says one of the trends he sees is the reduction in entrained air in brine. “This not only degrades ingredient functionality, but it also causes yield fluctuations because micronized air is injected instead of one-hundred percent brine,” Leitner says. “The entrained issue is becoming a huge issue for many processors who take the time to identify it.”

Manchester, N.H.-based Admix designs and offers its Rotomaxx™ series of all stainless-steel, very low-speed agitators to maintain suspensions in hold tanks that maintain 100-percent product uniformity without any air entrainment. The company makes manufacturing equipment specifically for providing the highest rate of ingredient functionality.

Admix’s brine-room technology includes high-shear brine make-up mixers designed to wet out and incorporate gums, spices and other solids, plus all stainless sanitary batch mixers for suspending and holding a brine slurry after make up and pre-pumping to injectors or tumblers. The company also makes Optifeed eductors to vacuum-feed dry ingredients ergonomically and the Boston Shearpump for creating fine meat emulsions.

Another trend is automation at all stages of the blending and grinding process to eliminate human error, says Eldon Roth, chief executive officer and president of Beef Products Inc. (BPI), Dakota Dunes, S.D.

“This is especially important as we see less commitment from equipment operators and automation of the process eliminates variability between individual operators, eliminating individual operator opinion for equipment operation,” Roth says. “We design all of our grinding systems to take advantage of the significant amount of mixing that occurs in the grinder itself if all components are fed into the first or course grind stage at the same time and at the approximate final lean target.”

Along with automation, Leitner sees improvements in ergonomically lifting and dumping bagged ingredients. He counts among the hazards “operator back strains along with accidents where operators are climbing to dump bags and then slip and fall.

“There are now bolt-ons to existing systems such as the Admix Optifeed™ that allow processors to quickly add on to their existing brine systems to allow floor level, ergonomically correct ingredient addition to brine mix systems,” Leitner says.

One of the primary challenges facing processors is over-blending or over-working product and the impacts of not obtaining an even blend, Roth says. “Grinding all meats together will help with this significantly. Once meats are ground separately, they become much harder to mix as they become much more sticky, and do not blend together appropriately,” he says.

Hoffmann agrees. “Often, the reduction of the blend cycle is counterproductive to maintaining product integrity and can jeopardize the homogeneity of the batch. Mastering blending technology and the applications is quintessential to applying the right solution for the job,” he says.

To tackle the challenges of blending and mixing, manufacturers have developed new equipment to meet these precise needs.

BPI offers a force-fed grinding system for coarse grinding with the approximated ratio of the final blend and jacketed mixers with intermeshing paddles; a patented frozen block grinding system with tempering device to grind and temper frozen product in approximately 10 seconds.

“BPI can deliver product from the grinder at precisely the temperature desired for blending,” Roth says. “Combined with our patented pathogen reduction process, we believe our integrated ground beef system will reduce E.coli. Our patented radius or beveled hole inlet grinding system produces a significant improvement in the defect removal process.”

Mepaco’s latest innovation is a mixer/grinder that features a unique overlapping or counter-rotating paddle design with bottom discharge and CO2 injection as an option. Mepaco’s high-capacity grinder offers finish grind capacities up to 550 pounds-per-minute, Hoffmann says.

AMFEC’s newest sanitary design mixer/blenders come standard with polished interior, quick-release shaft seals, toggle-locking doors, and agitators tailored to the customer’s product, Botto says. AMFEC also offers a vacuum mixer/massager that boasts the same features as its new mixer/blender, but it is also designed for both mixing and massaging in the same machine. “This is accomplished by a unique tub and agitator design,” Botto says.

And what does the future hold for blending? Leitner sees more a demand for complicated blends. “Consumer demands for new innovative flavor and fat profiles will likely cause ingredients to become further diverse and tougher to mix,” Leitner says.

Roth sees a drive toward even more automation. “Centralized grinding systems with total automation and systematic controls will be driven by costs, improvements in product consistency and quality, and the need for higher microbiological quality standards in order to maintain reputation as quality producers and avoid reputation-damaging product recalls.”

Hoffmann sees effects of the heightened awareness of food safety. “Reliability and food safety issues will continue to command attention, however, the challenge for blender manufacturers will be to develop innovative agitation technology, which allows customers to reduce blend and discharge times without sacrificing product quality or consistency.”

This awareness will bring even more improvements, Botto says. “Food safety concerns could bring agents that kill bacteria to be incorporated into the meat at the blending stage. The food industry’s concern for food safety is influencing the manufacturers of equipment to search for ways to improve equipment design and function to address the industry’s food safety concerns,” Botto adds.

Botto admits the industry may be slow moving in some regards. “The future of blending? Well, we haven’t come too far over the last thirty years. But as today’s technology filters down to our industry, I am sure we will see more changes.

“Today’s combos off the kill floor come with fat percentages that we combine to make our formulas,” he adds. “Perhaps we will have formula-ready combos – similar to case-ready ground beef – that come from the slaughterhouse to the processor ready to be ground with no further analysis needed.

“What would be of interest are continuous fat analyzers,” Botto continues. “As far as I know, although people claim they have workable units, there is no unit yet that does a reliable job.”

Botto issues a challenge to the meat industry. “What the industry needs is a ‘silver bullet,’ a machine that can instantaneously analyze all the product going to the blender and make adjustments on a continuous basis.” NP

Shonda Dudlicek is a freelance writer in the Chicago area.

Technology providers participating in this article include:

• Admix Inc., phone (800) 466-2369, fax (603) 627-2019

• American Food Equipment Co. Inc./Reiser, phone (781) 821-1290, fax (781) 821-1316

• Barliant and Co. phone (630) 553-6992

• Beef Products Inc., phone (605) 217-8000, fax (605) 217-8001

• Mepaco, phone (920) 356-9900, fax (920) 887-0206